In general, a part of a seat for vehicle can be attached to and removed from a car body floor to effectively utilize a restricted inside space of the vehicle. For example, in a motor omnibus of a van type, seats located on a rear part of a driver's seat can be attached or removed for loading goods.
However, a conventional attaching and disconnecting seat mechanism for a seat of a vehicle has a complicated structure, in which latch parts caught on front and rear wheels and strikers mounted on a lower frame, links for operating the components and various levers are connected to one another, and thus there is a difficulty in operation and a manufacturing cost is increased due to the complicated structure.